According to recent data from the literature, the deep layers of the abdominal and the autochthonous back muscles are essential for the stabilization of the spinal column, in particular of the lumbar spine. None of the papers published, however, takes into account the diaphragm and especially the pelvic diaphragm which are essential for trunk stability, guaranteed by the abdominal cavity. The paper deals with symptoms due to pelvic diaphragm dysfunction, and its treatment by active contraction and relaxation. The immediate release of back muscle spasm and trigger points at the diaphragm is described, and the relief of a chain of symptoms due to this dysfunction. The therapeutic effect shown by preliminary results is very promising.

        Key words: the stabilizing system, the pelvic diaphragm, active contraction and relaxation, muscle spasm, chain reaction